AT ONE BLAST.

Shannon News, 28 September 1923, Page 3

AT ONE BLAST.

9000 TONS OF METAL FOR ROADING

At a cost of about £SOO some 9000 tons of solid rock, which stood on the banks of tbe .Waikato. River, between Mercer and Tuakau, was broken up recently at one blast. The metal obtained as a result of this''operation is to be used for road formation, and particularly in connection with the work at Rangiriri. Before .the actual firing of tbe charge which loosened so much ,valuable metal, there was much preliminary work), extending over several weeks, that had to be carried out. The solid rock hai to be penetrated by a drive 45ft deep and three feet wide. For about live feet on either side of the main turn,el a cross-drive was made, and. in it it e explosives, about a. ton in weight, and sealed with concrete, were placed. Considerable interest was manifested in the final act which would bring the mass crumbling down. A number of launches journeyed "Tom Me/;;r. to Tuakau, and spectators we v landed on the other side of fi e river, where ‘a good view of .the proceedings could he obtained, while at the same time safety could he observed. The current was switched on from behind the quarry and the hill was seen to heave. The’ next- instant- there was a brilliant flash and a deafening explosion. and then a, shower of small stones shot up to fall into the river. A number fell among Ihe spectators on the opposite banks, a distance, of nearly ,900 yards. On examination H I was found that the whole face of the bluff, which was. 60ft to 80ft in height and several chains in breadth and depth, had been opened. As the result of Ihe big explosion only small shots 1 will he required in future quarrying.